Laserfiche WebLink
1.0 Placer Gold Mine Plan <br />1.1 General Plan Gold Minin <br />Past mining history has shown that significant gold placer deposits are found in dips or depressions <br />in the bedrock within the permit area. Good concentrations can also be found in previous locations <br />of the South Platte River channel. Recent seismic testing of the exact bedrock location (2002) has <br />shown some dips and an older channel location neaz the west edge of the permit azea. Based on this <br />testing and past operations, this area will be targeted for mining. The seismic cross-section locations <br />aze shown On Map C-1 and Map C-2. The actual cross sections showing the bedrock as well as the <br />current surface aze given in Appendix D. It is expected that 15 to 20 feet of overburden gravel will <br />be excavated and placed in previous pit excavations to get to the lower 5-10 feet of gravel above the <br />bedrock, which is known to contain the high gold concentrations. In virgin azeas, soil from 3" to 9" <br />is salvageable and will be stockpiled as shown on Map C-2. The expected average is 4.5" based on <br />existing cuts of the surface. <br />The azeas will be mined in strips of approximately 300 feet long by 150 feet wide with 2H:1 V <br />sideslopes to get to the bedrock. These sequential cuts aze labeled on the mine plan. Prior to any <br />mining for this amendment, a gravel berm of a minimum of 8' height, 2H:1 V sideslopes will be cre- <br />ated along the Highway 9 ROW for at least a 600' length around the active mining area. This will <br />visually shield the operation from the Highway, as well as minimize noise impacts. Dust should be <br />minimized since much of the mining will take place below the water table, therefore, the material to <br />be mined will be wet. Almost all of the gravel sent to the prep plant will be wet. <br />The operation will resemble a coal strip operation since dozers, loaders and trucks will be used to <br />move the overburden from the azea to be mined to the adjacent previously mined azea. While the <br />previous mined area is being graded, the lower portion of the gold-beazing gravel will be mined by <br />loader loading into a rock grizzly with 5" openings to ensure that only -5" material enters the porta- <br />ble 36" conveyor system, which will transport the material to the fixed plant location shown on Map <br />C-2. The initial 2-3 cuts may utilize trucks to transport the gold-bearing gravel to the plant since <br />Alma Placer 7/03 9 <br />